The United States and European nations said on Tuesday that the Russian government was behind the attack that took down satellite communications in Ukraine.

The governments blamed Moscow but didn't name the organization that blacked out Ukrainian communications. The G.R.U., the Russian military intelligence agency, was responsible for the hack of the Democratic National Committee and other attacks, according to American officials.

This unacceptable cyberattack is yet another example of Russia's continued pattern of irresponsible behavior in cyberspace, which also formed an integral part of its illegal and unwarranted invasion of Ukraine.

The Ukrainian government used a system run by Viasat, a California company that provides high-speed satellite communication services. A few weeks ago, some Ukrainian government websites were hit with a software that destroys data.

American and European officials said that the Viasat attack was intended to disrupt the command and control of the Ukrainian troops. Thousands of people in Europe and Ukraine were cut off from the internet. It prevented the operation of thousands of wind turbine in Germany that relied on Viasat's technology for monitoring conditions and controlling the turbine network.

Viasat called in Mandiant to write a report after launching an investigation. In March, Viasat published initial conclusions, but the deeper studies have not been made public.

The initial conclusion was that the hackers never had to attack the satellites themselves. They focused on the ground-based modems that communicated with the satellites. A senior government official said that the vulnerability of those systems was a wake-up call, raising concerns that Russia or China could exploit similar vulnerabilities in other critical communications systems.

The disruptions caused by the Viasat hack showed how quickly a cyberattack can spread, as US and European officials cautioned that cyberweapons are often unpredictable. The operations of Maersk, the Danish shipping conglomerate, and other major companies were disrupted by the NotPetya cyberattack.

The Viasat hack showed a weakness in the service that was exploited by Russian hackers without much technical sophistication. The meeting between President Biden and President Putin of Russia took place in June of last year. Mr. Biden warned Mr. Putin against attacks on the U.S. infrastructure. The Viasat attack was directed at an American company.

The cyberattack against Viasat was believed to have been carried out by Russia, but officials in the United States and Ukraine didn't officially attribute it to Russia. European nations were asked to take the lead by the U.S. officials since the attack had significant ramifications in Europe but not in the US.

The statements released Tuesday stopped short of naming a particular Russian-sponsored hacking group for orchestrating the attack, an unusual omission as the United States has routinely revealed information about the specific intelligence services responsible for attacks.

Viasat has and will continue to work closely with relevant law enforcement and governmental authorities as part of the ongoing investigation. Mandiant, the firm hired by Viasat to investigate the matter, refused to comment on its findings.

The Viasat hack was thought to be the work of the G.R.U., Russia's military intelligence unit. The G.R.U.'s previous use of different types of malicious software, such as AcidRain, shared significant similarities with the one used in the attack.

AcidRain was created as a multi-purpose tool that could easily be used against a wide variety of targets, researchers said. The Justice Department and the Federal Bureau of Investigation said that Russia was behind the creation of the software.

The AcidRain is a very generic solution that can be used tomorrow.

The U.S. has warned that Russia could carry out a cyberattack against the U.S. critical infrastructure. The State Department said that the U.S. has aided Ukraine in detecting and responding to Russian cyberattacks.

As nations committed to uphold the rules-based international order in cyberspace, the United States and its allies and partners are taking steps to defend against Russia's irresponsible actions.

The United Kingdom will continue to help Ukraine fight cyberattacks.

The security and intelligence service of Ukraine said in a statement that all the countries should unite their efforts to stop the invaders.